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===== Background Map =====

Background Map (GSHHS Low Res) - Crude Resolution basemap Installed with Opencpn for the initial rough background map. By default, under macOS, it is installed in Contents/SharedSupport/gshhs/ subfolder of the application bundle.

  * [[http://www.soest.hawaii.edu/pwessel/gshhg/|GSHHG A Global Self-consistent, Hierarchical, High-resolution Geography Database]]

==== GSHHG High Resolution Background Map ====

High resolution background maps can be obtained through the integrated Chart Downloader plugin see [[https://opencpn.org/wiki/dokuwiki/doku.php?id=opencpn:opencpn_user_manual:charts:chart_sources#high_resolution_background_map|GSHHS High Resolution Background]] Use with Watchdog Landfall alarms and WeatherRouting plugins for land detection.

      * Path to this dataset is stored in the //BasemapDir// configuration key in //opencpn.ini//. 
      * As long as it points to //Contents/SharedSupport/gshhs///, replacing the content of //Contents/SharedSupport/gshhs/// makes OpenCPN use it. 
      * If //BasemapDir// points somewhere else, it is not going to be used.
      * However if GSHHG data is pointed to a //chart folder//, the folder is detected and //BasemapDir// is changed to point to that location.
      * //Basemap// is always displayed, regardless of chart groups.
      * Keep your GSHHG dataset up to date using //ChartDownloader//, please.

The GSHHG High Resolution Background Map is very useful and almost necessary for two plugins that actively use it:
  * **Watchdog_pi**  - For Landfall notification
  * **Weather_routing_pi**  - For routing optimization with Land Detection.
